Please explain me how to find lub and glb of the sets (-1,1), [2,5) and {pi+1,pi+2,pi+3,.....}
Please help..
If you are just trying to find them this is simple. $\displaystyle \sup\text{ }(-1,1)=1$, $\displaystyle \sup\text{ }[2,5)=5$ and the supremum of $\displaystyle \left\{\pi+n:n\in\mathbb{N}\right\}$ does not exist since the set is unbounded from above.